<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const arr = [
        { id: "29", pid: "", name: "总裁办" },
        { id: "2c", pid: "", name: "财务部" },
        { id: "2d", pid: "2c", name: "财务核算部" },
        { id: "2f", pid: "2c", name: "薪资管理部" },
        { id: "d2", pid: "", name: "技术部" },
        { id: "d3", pid: "d2", name: "Java研发部" },
        { id: "d31", pid: "2f", name: "Java研发部111" },
      ];

      // 使用递归来实现 平铺结构 转树形
      // 两个参数  要转会的数组arr  第二个参数，就是要转换的父id
      function transformListToTree(arr, pid) {
        function recursion(pid) {
          const res = [];
          arr.forEach((item) => {
            if (item.pid === pid) {
              res.push(item);
              item.children = recursion(item.id);
            }
          });
          return res;
        }

        return recursion(pid);
      }

      const newArr = transformListToTree(arr, "");
      console.log(newArr);
    </script>
  </body>
</html>
